Press guard



July '4, 1950 w. s, WlLKlNS PRESS GUARD Filed July 1?;1945

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-- Immun- Patented July 4, 1950 PnEss GUARD Walter S. Wilkins, Wednesbury, England, assignor to Wilkins & Mitchell, Limited, Darlaston, England Application July 17, 1946, Serial No. 684,104 'In Great- Britain July 21, 1945 The invention relates to guards for power presses and has for its object to effect improvements therein.

Heretofore usually guards for presses have been operated by the moving head of th press; but according to the present invention they are opened and closed by hand, locking means being provided to ensure that the guard can only be opened when the head of the press is fully up; and the press cannot be started with the guard open.

While the invention is applicable to a press having only a front guard, it is more especially applicable to a press in which there are two operators (and two guards), one at the front of the machine and one at the rear. In the latter case locking means are provided which prevent the opening of the rear guard until the front guard is opened and the closing of the front guard until the rear guard is closed.

According to an important feature of the invention each guard is dividedlongitudinally into an upper and lower part each guided for vertical movement, the arrangement being such that, when the top part is moved up, the lower part moves down.

A convenient embodiment of: the invention, as applied to a press having a front and a rear guard, is described with reference to the accompanying drawings; in which:

Figure 1 is a front elevation, partly broken away, of the press, showing the front guard in the closed position and showing a vertically moving head in its upmost position.

Figure 2 is a view partly broken away, of the right hand end of the press, also showing the head in its upmost position and showing both guards closed.

- Figure 3 is a view partly broken away, of the left hand end of the press showing the moving head raised, and both guards closed.

Figure 4 is a view, corresponding to Figure 3, but showing both guards open.

Figure 5 is a view in somewhat diagrammatic form illustratingamodification.

In these drawings, the number 1 indicates the moving head of the press and 8 indicates the usual fixed table or bolster, l0 indicates the main frame of the machine having at its two sides two front guides l l, l I, in which slide upper and lower 6 Claims. (01.192-134) guard frames l2, l3. I4 is a shaft passing across the front of the upper part of the press and being journalled in bearings l5, l5, secured to upward extensions of the guides H, II. The shaft M has rigidly mounted thereon two sprocket wheels 16, IB, with the teeth of which engage endless chains ll, H, which also pass round sprocket wheels l8, l8, rigidly mounted on a shaft l9 journalled in bearings 26, 20, secured to downward extensions of the guides H, H. The lower guard 13 is anchored at its two sides to the front portions of these chains by brackets 2|, 2i, and the upper guard I2 is anchored to the rear portions of these chains by brackets 22, 22. The guard frames are opened and closed by hand; and, owing to their being coupled by the chains, the raising of the one causes the lowering of the other.

This method of coupling the two frame parts together has the advantage that the one frame balances the weight of the other. The forming of the guard in two parts has the advantage that each of the frame parts needs to be moved on half the distance which would be required for a single piece guard. h

The shaft l4 carries at its right hand end a disc 23 having a radial slot 24, see Figure 2. When the frames I2 and iii are closed the disc 23 will have been turned by the shaft M to such position that the slot is directed vertically upward (see Figure 2).

The clutch which causes the engagement of the gear which raises and lowers the moving head is operated by an air valve 25 coupled to a vertical rod 26 joined at its lower end to a hand lever 21. The rod 26 carries a plate 28, which when the rod is moved down can enter the said slot 24, when the latter is extending vertically upward as it is when the frames [2 and 13 are closed. Thus the press can be started when the frames 12 and 13 are closed. When, however, the frames l2 and I3 are open the slot 24 is not opposite the plate 24, so that the latter cannot enter the slot and can only ride on the periphery of the disc 23. Thus the rod cannot be depressed to start the machine except when the frames l2 and it are closed. 7

41 is a trip lever having a downward arm 44 carrying a roller 45 which is engaged by an abutment 45 on the moving head, so placed that the lever 41 is rocked to stop the press each 5 notch in the disk at the front end of the press is opposite the respective V-shape bar, so that the bar may be forced out of the respective notch by the turning of the respective disk, the front end of the bar entering the notch in the front disk, whereby the rear guard can be opened and the front guard is locked in the open position and can not be closed until the rear guard is closed.

WALTER SAMUEL WILKINS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Number Name Date Heating May 4, 1909 Rashkin May 23, 1911 Martin Sept. 12, 1922 Napier May 8, 1934 Waldman Aug. 9, 1938 Norton et a1 Nov. 3, 1942 Wells Aug. '7, 1945 FOREIGN PATENTS Country Date Great Britain Mar. 14, 1940 

